Talk of the possible deal sent shares of the Oslo, Norway company up as much as 26 percent.

Opera's browsers work across a number of platforms, including mobile phones, tablets, PCs and TVs.

Reuters quoted analysts on Tuesday who said Opera would make a perfect fit for Facebook (NASDAQ:FB) since the browser works on iPhones, Blackberries and devices that use Google Inc.'s (NASDAQ:GOOG) Android operating system.

One potential block to such a deal, however, is that Opera and Google have worked closely together.